Ontario data centres and grid planning

The Greater Toronto Area contains the largest share of Ontario records in this directory. Toronto, Markham, Vaughan and Brampton include carrier hotels, enterprise facilities, hyperscale buildings and operator campuses. The expanded collection also includes Ottawa, London, Hamilton and Barrie. These localities serve different network and operating roles, so a provincial total should be read alongside city, operator, building type and publication state.

Sources: Equinix, Digital Realty, Rogers Business, Shared Services Canada

Several provider records can refer to services inside the same major carrier building. That is not an error, but it is a reason to avoid treating every listing as a separate purpose-built campus. The facility page names the operator represented by the source and keeps near-duplicate pages out of the index until the record has differentiated specifications and a uniqueness review. Researchers should distinguish physical building, operator presence and marketed facility name.

Sources: Telehouse Canada, Cologix, Canadian Web Hosting

Ontario reports a 2024 electricity mix led by nuclear generation, followed by hydroelectric output, natural gas, wind and smaller solar and bioenergy contributions. Nuclear and hydro provide much of the year-round energy. That mix can support a low-emission operating case, but a project still depends on the transmission and distribution system serving its chosen location. Provincial energy composition does not answer whether a specific transformer station can accept a new large load.

Sources: Government of Ontario

The provincial energy plan expects data centres to contribute materially to new demand by 2035. Ontario has also moved toward explicit approval for certain large data-centre connections so electricity can be assigned according to public and economic priorities. A developer must therefore track both the established technical connection process and the current provincial approval framework. A site that is close to fibre and customers may still face a power-allocation decision.

Sources: Government of Ontario

Hydro One describes a seven-phase process for transmission load connections. It begins with the connection application and proceeds through impact assessment, estimates and approval. The IESO Connection Assessment and Approval process runs in parallel to determine effects on the reliability of the controlled grid. These are not paperwork steps added after site selection. They are core feasibility work that can alter the preferred point of connection, project scope, schedule and cost.

Sources: Hydro One

IESO technical requirements for large computational loads call for a System Impact Assessment and project data that reflects the behaviour of the proposed load. A data centre can have fast ramps, power-electronic interfaces and operating modes that differ from a conventional industrial plant. The applicant needs credible models for normal operation, disturbances and recovery. Generic statements about a redundant utility feed do not replace the project-specific studies required by the system operator and transmitter.

Sources: Independent Electricity System Operator

The Ontario Energy Board explains that an electricity bill can include the energy charge, Global Adjustment, delivery and regulatory charges. Delivery rates vary by utility and location because network condition, customer density, geography and system design differ. Large users may face structures that are not represented by residential or small-business price plans. A data-centre model should identify the applicable customer class, wholesale exposure, transmission and distribution charges, losses and peak-related obligations.

Sources: Ontario Energy Board

This is why a single Ontario cents-per-kilowatt-hour comparison is weak evidence. Two projects with the same annual energy can have different costs because of demand profile, service voltage, peak contribution, connection assets and local delivery tariffs. The public pages here describe the structure and direct readers to the authority. They do not publish a universal project rate or turn a current tariff into a long-term financial forecast.

Sources: Ontario Energy Board, Hydro One

Telehouse Canada publishes three downtown Toronto facilities at 151 Front Street West, 250 Front Street West and 905 King Street West. The operator states that the sites are linked by dark fibre. It publishes 20 MW and 205,000 square feet of IT space for 151 Front, and 10 MW values for each of the other two sites. These figures help differentiate the buildings, but the source does not promise that the full figure is available to a new customer.

Sources: Telehouse Canada

Digital Realty publishes three Toronto-area facilities with different sizes and locations. Equinix and Cologix publish additional downtown and suburban sites. The result is a layered metro: dense carrier access in central buildings, larger footprints in Markham and Vaughan, and regional options beyond the core. Workload placement may use more than one layer, with interconnection in a carrier hotel and compute or recovery capacity elsewhere.

Sources: Digital Realty, Equinix, Cologix

Use the record table to compare locality, operator, operating state, last check date and published specifications. Provider claims remain labelled as such. Certifications are shown only when the checked source names them. Building size is not converted into IT capacity, and a campus total is not assigned to every building. If a field is unverified, treat it as a request for current operator documentation rather than a negative finding.

Sources: Digital Realty, Telehouse Canada

A project shortlist should then be tested against the grid path, network routes, travel and maintenance access, expansion sequence and the workload's recovery needs. Ontario offers a large customer base and deep connectivity, but current policy and connection studies make electrical feasibility an early gate. The best-known address is not automatically the best place for every load, and a published facility count is not evidence of unused provincial capacity.

Sources: Government of Ontario, Independent Electricity System Operator